Of the world's 37 species of cats, eight reign as the big cats. All are top predators in their realm. All are losing ground. More people are living in their range. They face habitat loss, illegal hunting for skins and other body parts, and retaliatory killing when they prey on livestock. Yet conservationists see hope, if there's concerted effort. As field biologist George B. Schaller writes, "The great cats represent the ultimate test of our willingness to share this planet with other species."

Capturing a lion, tiger, or leopard on camera is challenging enough for most photographers. Now imagine persuading a big cat to pose for a studio-style portrait.

For the magazine's "Cats in Crisis" poster, National Geographic photographer Vincent J. Musi wanted to light the animals in a way that would truly showcase their muscular grace, piercing gazes, and gleaming coats.

"These animals were not actors; they weren't under control or chained," Musi says. "We were trying to do something different."

He turned to the Houston Zoo, which had seven of the world's big cat species. (Musi photographed the eighth, a snow leopard, at Mill Mountain Zoo in Roanoke, Virginia.) The zoos let him work in a small holding area adjacent to the animals' main living areas, enabling him to get much closer to the cats than most people (or photographers) ever do.

And then the challenge begins. "You've got to look at his space, where he's comfortable, and say: How can we make this work?" Musi recalls.

He rigged up strobe lights and makeshift black backdrops of paint, plywood, and paper. Then it became "a waiting game," with Musi standing behind a chain-link fence for protection.

It could be a long time before the cat entered the space and relaxed enough to settle in a suitable spot.

"The lion was tough, too. He was too curious and wanted to get close the whole time. He would just plop down right in front of me, and it looked like his head was the size of a Dumpster!"

The animals were never more than eight feet away, which could be a little unnerving for both parties. And while the cats look glamorous, Musi's experience was not. "You're sitting, kneeling, or laying down, sometimes in cat urine, for 8 to 12 hours a day. It smelled nasty. Not to mention their breath!"

The snow leopard reacted to the photographer's presence by "yelling," making it impossible to get a good picture—until Musi decided that two could play that game.

"I don't know what happened, but I hit some point where I got fed up with her and just started to rant," Musi says. "I started talking about the Hindenburg disaster, Elvis Costello, whatever. The snow leopard just totally shut down and stared at me like she couldn't believe it." —Amanda Fiegl

Neofelis nebulosaSmallest of the big cats—males may reach 50 pounds—it has canine teeth as long as a tiger's. An acrobatic climber, it hunts in trees as well as on the ground in forests across Southeast Asia.

Panthera unciaThe "ghost of the mountains" is at home in the Himalaya and surrounding ranges of Central Asia. In 1971 this magazine was the first to publish photos of the elusive cat taken in the wild.

Puma concolorCougar, mountain lion, panther: The cat of many names ranges from Canada to the tip of Chile. It's returning to former lands in the U.S. Midwest, but overall population is thought to be falling.